Imagine the emotions of Queen Elizabeth II when she was told that in this, her Diamond Jubilee year, she must shake the hand of Martin McGuinness, the former IRA gunman, at a ceremony in Northern Ireland next week.

Her initial reaction must have been utter revulsion at the thought of having to undergo any social connection with the man who sat on the IRA’s inner councils when they plotted to murder her husband Prince Philip’s beloved uncle, Lord Mountbatten of Burma.

For over four decades, McGuinness was at the apex of a terrorist organization whose campaigns led to the death of 3,524 of her majesty’s subjects, on both sides of the sectarian divide.

Her next emotion would have been resigned acceptance that this is part of the duty of a head of state in a period of reconciliation. She has shaken hands that were dripping with the blood of innocents before, such as those of Idi Amin and Robert Mugabe. She even had to invite Nicolae Ceaucescu to Buckingham Palace when the British government was trying to woo Romania away from the Russian orbit in the 1970s.

Of course, none of those killers had murdered her cousins as the IRA have, but she realizes better than most that, in the words of the Conservative MP and former Army Col. Patrick Mercer, “It is hard to swallow, but reconciliation is reconciliation.”

One hopes that the queen’s final thought on the subject — after making a note to wear gloves that day — was to recognize that this is far, far more of a humiliation for Irish republicanism than it is for the British monarchy.

The symbolism could not be more powerful: The IRA is finally shaking hands with the British Crown while Northern Ireland remains part of the United Kingdom. The will of the majority of the people of Northern Ireland has won out.

McGuinness is now deputy first minister of one of the queen’s provinces, meeting his anointed monarch and head of state. His defeat is total.

Although the start of the peace negotiations preceded 9/11, it was the attack on the Twin Towers that finally persuaded the IRA’s leaders that the game was up for their long campaign to detach Northern Ireland from the rest of the queen’s realm. Having seen firsthand the horrors of terrorism in their own country, no longer would Irish-Americans continue to help finance an organization whose methods routinely encompassed the slaughter of innocents.

After that, it was just a question of coming to appropriate terms. The IRA ended its armed struggle and handed over its weapons for international decommissioning. In return, its gunmen were released from prison; McGuinness and others later accepted ministerial offices under the crown.

Yet in a place like Ulster where symbolism is everything, there is a world of difference between McGuinness being chauffered around in a government ministerial car and his actually shaking the hand of a (doubtless suitably-gracious) queen in front of the world media.

After a lifetime of trying to wrest power from the crown, he has had to accept office from that selfsame crown with as much good grace as he can muster — and now shake the hand of the present wearer of that crown into the bargain.

The IRA-Sinn Fein leader Gerry Adams has had to hold no fewer than 40 meetings with former IRA killers, Sinn Fein politicians and their supporters and sympathizers to explain why McGuinness has had to take this step. Some of the meetings were reported to have been (understandably) stormy. Loathing of the crown and the House of Windsor are deeply embedded in Irish republicanism, an integral part of its DNA.

The Sinn Fein-IRA members whom Adams met were brought up to abhor the crown; it came with their mother’s milk. Small wonder they hate the prospect of this handshake — for it represents nothing less than their complete and utter defeat.